The communication of data over networks has become an important, if not essential, way for many organizations and individuals to communicate. The Internet is a global network connecting millions of computers using a client-server architecture in which any computer connected to the Internet can potentially receive data from and send data to any other computer connected to the Internet. The Internet provides a variety of methods in which to communicate data, one of the most ubiquitous of which is the World Wide Web. Other methods for communicating data over the Internet include e-mail, usenet newsgroups, telnet and FTP.
Users typically access the Internet either through a computer connected to an Internet Service Provider (“ISP”) or computer connected to a local area network (“LAN”) provided by an organization, which is in turn connected to an ISP. The network service provider provides a point of presence to interface with the Internet backbone. Routers and switches in the backbone direct data traffic between the various ISPs.
As the number of networked devices has increased, so too has the amount and nature of network traffic. One unfortunate side effect is the evolution of destructive or unauthorized access to the data or operations of networked devices. As a result, technological advances have produced a general class of network service known as a “firewall”, which can block or limit access to computers, networks and services “inside” the firewall, from access by any network devices “outside” the firewall. Representation of “inside” and “outside” a firewall is analogous to physical security and protection, where something “inside” is protected from something “outside”. Hence, firewall technology and services normally have one network interface connected to the general internet or an unprotected segment of any network and the protected computer and network assets are located behind another network interface controlled by the firewall that is a different, protected network segment.
Typically, network firewalls are configured in a static manner, wherein the firewall's configuration is established and changes infrequently.
Firewalls are potentially complicated structures that are generally maintained manually by a skilled professional. Firewall owners must therefore limit themselves to simple and inflexible features provided by typical network applications/devices, or they must invest in professionals who are skilled enough to construct and maintain firewalls to their specifications. In other words, the skilled firewall professional provides the intelligence, decision-making and flexibility that is lacking in static firewall technology.
Previous firewall implementations are typically limited in two ways: (1) they are embedded in an inflexible hardware platform with no ability to expand and/or (2) they offer only a very simple set of user-visible features both because they have no expandability and because they lack the conceptual model to express more advanced features in a way that is convenient for customers to use. These solutions are inadequate because they limit the power of the features available to customers.
While statically configured firewalls serve a purpose for protecting static network and computing assets, the ability to dynamically reconfigure firewalls in a changing network environment represents a significant evolutionary step in network firewall technology. Dynamic firewalls can monitor transient network client connections and adjust themselves to optimally serve and protect a dynamically changing network client population on both “sides” of a firewall.